The man who started planning Queen Elizabeth II' s lying-in-state and funeral 23 years ago, has revealed the enormous amount of detail and effort that went into the whole arrangement.
Lt Col Anthony Mather began writing 'London Bridge', the code name given for what would happen when the Queen died, in 1999, when Her Majesty was in her 70s.
He led a team of 300 people, who would meet once a year to revise the plans and coordinate with courtiers.
